INSman it was a bone in from a high quality butcher shop. I believe the exceptional quality of the meat and the recipe made the primerib as good as any resturant i have had prime, and i have been to quite a few that are notorious for their prime rib.
I would say the same and I have been to some of the best and my first roast was only a "Choice" cut, but "Prime" is next !!!
I used a hodge podge seasoning mix that also seemed to work VERY well that included Montreal Steak seasoning, seasoned pepper, dried rosemary and a little bit of "Herbes de Provence" that I cannot remember where I got from, but added a little extra flavor on the herb side.